#!/usr/bin/env python

"""

Tests helpers in `can.interfaces.socketcan.socketcan_common`.

"""

import unittest

from pathlib import Path

from unittest import mock

from can.interfaces.socketcan.utils import error_code_to_str, find_available_interfaces

from .config import IS_LINUX, TEST_INTERFACE_SOCKETCAN

class TestSocketCanHelpers(unittest.TestCase):

@unittest.skipUnless(IS_LINUX, "socketcan is only available on Linux")

def test_error_code_to_str(self):

"""

Check that the function does not crash & always

returns at least one character.

"""

# all possible & also some invalid error codes

test_data = list(range(0, 256)) + [-1, 256, 5235, 346264, None]

for error_code in test_data:

string = error_code_to_str(error_code)

self.assertTrue(string) # not None or empty

@unittest.skipUnless(

TEST_INTERFACE_SOCKETCAN, "socketcan is only available on Linux"

)

def test_find_available_interfaces(self):

result = find_available_interfaces()

self.assertGreaterEqual(len(result), 3)

self.assertIn("vcan0", result)

self.assertIn("vxcan0", result)

self.assertIn("slcan0", result)

def test_find_available_interfaces_w_patch(self):

# Contains lo, eth0, wlan0, vcan0, mycustomCan123

ip_output = (Path(__file__).parent / "data" / "ip_link_list.json").read_text()

with mock.patch("subprocess.check_output") as check_output:

check_output.return_value = ip_output

with mock.patch("sys.platform", "linux"):

ifs = find_available_interfaces()

self.assertEqual(["vcan0", "mycustomCan123"], ifs)

def test_find_available_interfaces_exception(self):

with mock.patch("subprocess.check_output") as check_output:

check_output.return_value = "<h1>Not JSON</h1>"

result = find_available_interfaces()

self.assertEqual([], result)

check_output.side_effect = Exception("Something went wrong :-/")

result = find_available_interfaces()

self.assertEqual([], result)

if __name__ == "__main__":

unittest.main()